Solra Bizna
I have written a program that, in the event that the user requests more MSAA samples than their hardware supports, attempts to gracefully fall back to the best MSAA available. This code works with my conventional OpenGL renderer, but if I change nothing about the code except to make it request an OpenGL ES profile instead, Xlib kills the program with an error that looks like:
X Error of failed request: BadWindow (invalid Window parameter)
Major opcode of failed request: 4 (X_DestroyWindow)
Resource id in failed request: 0x5c00008
Serial number of failed request: 188
Current serial number in output stream: 193
To trigger the bug, attempt to create a window with the SDL_WINDOW_OPENGL flag, with SDL_GL_CONTEXT_PROFILE_MASK set to SDL_GL_CONTEXT_PROFILE_ES, and with SDL_GL_MULTISAMPLESAMPLES set to any unsupported value. SDL_CreateWindow properly returns NULL, but at this point the program is already doomed. Xlib will shortly terminate the program with an error. Calling SDL_CreateWindow again will immediately trigger this termination.
I have attached a skeletal program that reproduces this bug for me. Replacing SDL_GL_CONTEXT_PROFILE_ES with SDL_GL_CONTEXT_PROFILE_COMPATIBILITY avoids the bug (but, obviously, doesn't create an OpenGL ES context).
As I suspected, the problem was with XDestroyWindow being called twice on the same window. The X11_CreateWindow function in src/video/x11/SDL_x11window.c calls SetupWindowData. If initialization fails after that point, XDestroyWindow gets called on the window by a subsequent call to X11_DestroyWindow. But, later in the same function, iff a GLES context is requested and initializing it fails, X11_XDestroyWindow (which wraps XDestroyWindow) is manually called. Shortly after, the intended call to X11_DestroyWindow occurs, which attempts to destroy the same window again. Boom.
(The above confusing summary involves three separate, similarly-named functions: XDestroyWindow, X11_DestroyWindow, X11_XDestroyWindow)
I have attached a simple patch that removes the redundant X11_XDestroyWindow calls. I've tested that XDestroyWindow still gets called for the windows in question, and that it only gets called once.
- _num_clips was not set in constructor, so a NULL _clips could be
mistakenly dereferenced.
- As _clips is accessible outside the class, it is not a good idea to
free/reallocate it. Try to limit this by reallocating only when it needs to
grow.
Partially fixes Bugzilla #4442.
This can happen if a window is still grabbed when we try to move it, or if
the X11 ecosystem is just in a bad mood, I guess.
This makes sure that SDL will report the correct position for a window;
otherwise, SDL_GetWindowPosition will just report whatever the last
SDL_SetWindowPosition call requested, even if the window didn't actually move.
Fixes Bugzilla #4646.
Much of the heavy lifting of this optimization is lifted from the Pixman
project, which is distributed under an MIT-style license. As far as possible,
these elements have been relicensed to the zlib license.
Fixes an issue in macOS 10.15 where the displayed content would move up after entering, exiting and re-entering exclusive fullscreen when certain display modes were used (bug #4822).
Bug #3949 is also related to this change.
Use eglGetProcAddress for everything on EGL >= 1.5. Try SDL_LoadFunction first
for EGL <= 1.4 in case it's a core symbol, and as a fallback if
eglGetProcAddress fails. Finally, for EGL <= 1.4, fallback to
eglGetProcAddress to catch extensions not exported from the shared library.
(Maybe) Fixes Bugzilla #4794.
Sylvain
Seems to be a regression in this commit: https://hg.libsdl.org/SDL/rev/7fdbffd47c0e
SDL_CalculatePitch() was using format->BytesPerPixel, now it uses SDL_BYTESPERPIXEL().
The underlying issue is that "surface->format->BytesPerPixel" is *not* always the same as SDL_BYTESPERPIXEL(format);
BytesPerPixel defined as format->BytesPerPixel = (bpp + 7) / 8;
vs
#define SDL_BYTESPERPIXEL(format) ... (format & 0xff)
Because of SDL_pixels.h format definitions, one is giving a BytesPP 1, the other 0.
"This patch does the following:
* Instead of SDL_FillRects calling SDL_FillRect in a loop the opposite
happens -- SDL_FillRect (a specific case) calls SDL_FillRects (a general case)
with a count of 1
* The switch/case block is moved out of the loop -- it modifies the color
once and stores the fill routine in a pointer which is then used throughout
the loop"
Fixes Bugzilla #4674.
